She had always dreamed of attending Torrey Pines High, where her dad Gino taught math, and playing basketball, the sport her mom Cristina played in high school and college.

Nine games into the best time of her life, Sierra was felled. Not by an injury but by her own body.

Almost a year later, Campisano is not only back in school but is back on the basketball court with no complications from a dangerous bout with appendicitis that forced her to celebrate her 15th birthday on Dec. 28 during a three-week stay at Children’s Hospital.

“In the blink of an eye she went from being an elite athlete to deathly sick,” said Cristina, who was coached by father Larry Willis at Mission Bay High. “It’s a journey I don’t wish on anyone else and it’s one I never want to take again.”

Days after earning all-tourney honors in the Kiwanis Tournament, after a 27-point effort to cap the event, Campisano thought she had finally been hit by the flu bug that had been going through her team.

On Christmas Day, Campisano was rushed into emergency surgery because her appendix had burst.

“There was no appendix there,” she said, laughing.

In less than a month, Campisano lost 30 pounds down to 112.

“At 6-foot-2, 112 pounds is not a good look,” she said. “None of my clothes fit. I was in total disbelief when I saw what had happened to me.”

She wasn’t done, though. Her pain continued until a second surgery was needed to drain three abscesses that were the result of the infection from her appendix.

Instead of sitting out maybe three weeks, the emerging star did not return to action until Feb. 8 at Poway for the final three regular-season games and one playoff loss to Eastlake.

Through nine games as a freshman, Campisano was already among the top players in the county. She was averaging 19 points, 16.8 rebounds and 8.4 blocks a game.

Her return was nowhere close to where she was before her brush with death.

She averaged 13.8 points, 11 rebounds and 3.7 blocks a game, good by most players’ standards but not Campisano’s.

“I thought once the scars were healed I could start playing again,” Campisano said. “The doctor said I could play as soon as I felt good enough.

“But it took me weeks and weeks to be able to get into a slow jog. I’ve looked forward to this season ever since that Poway game last year because it seems like forever that I was 100 percent healthy.”

Never mind that the Falcons dropped a 62-57 decision at Poway in her return, and forget about scoring 17 points and grabbing 12 rebounds.

Just being back on the court with her teammates was enough.

“It put a smile back on her face,” said former Falcons coach Dave McClurg. “Seeing what she went through, I’m in her corner for life.”

Though she said she still can’t smile about last season, Campisano, who recorded a triple double with 27 points, 20 rebounds and 15 blocks in her varsity debut against Ramona in 2012, is close to her peak form as a sophomore.

In a 2-3 start for Torrey Pines, which is competing in the Kiwanis Tournament this week, Campisano averaged 21.4 points, 13.2 rebounds and 3.6 blocks.

“Basketball has been the one thing I’ve always loved,” she said. “I could always go shoot some hoops for a couple of hours.

“In the hospital, my mom and I watched a lot of college hoops on TV or videos of old TV shows from when she was a little girl.

“That’s a long way from going one-on-one in the backyard against her. She was always complaining to other parents about all the bruises on her arms from our little games.”